File: crypt.c

package info (click to toggle)
virtuoso-opensource 6.1.6+dfsg2-4
  • links: PTS, VCS
  • area: main
  • in suites: buster, sid, stretch
  • size: 260,992 kB
  • ctags: 125,220
  • sloc: ansic: 652,748; sql: 458,419; xml: 282,834; java: 61,031; sh: 40,031; cpp: 36,890; cs: 25,240; php: 12,692; yacc: 9,523; lex: 7,018; makefile: 6,157; jsp: 4,484; awk: 1,643; perl: 1,013; ruby: 1,003; python: 326
file content (158 lines) | stat: -rw-r--r-- 4,054 bytes parent folder | download | duplicates (2)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
/*
 *  crypt.c
 *
 *  $Id$
 *
 *  one-way crypting
 *
 *  This file is part of the OpenLink Software Virtuoso Open-Source (VOS)
 *  project.
 *
 *  Copyright (C) 1998-2012 OpenLink Software
 *
 *  This project is free software; you can redistribute it and/or modify it
 *  under the terms of the GNU General Public License as published by the
 *  Free Software Foundation; only version 2 of the License, dated June 1991.
 *
 *  This program is distributed in the hope that it will be useful, but
 *  WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 *  General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License along
 *  with this program; if not, write to the Free Software Foundation, Inc.,
 *  51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
 *
 */

#include "Dk.h"
#include <assert.h>


static int
mod95 (register int val)
{
  /* The mathematical MOD does not match the computer MOD  */

  /*
   * Yes, what I do here may look strange, but it gets the job done,
   * and portably at that.
   */

  while (val >= 9500)
    val -= 9500;
  while (val >= 950)
    val -= 950;
  while (val >= 95)
    val -= 95;
  while (val < 0)
    val += 95;
  return (val);
}


static void
ue_crypt (register char *bptr, register int len)
/* register char *bptr;  buffer of characters to be encrypted */
/* register int len;     number of characters in the buffer */
{
  register int cc;		/* current character being considered */

  static long key = 0;		/* 29 bit encryption key */
  static int salt = 0;		/* salt to spice up key with */

  if (!bptr)
    {				/* is there anything here to encrypt? */
      key = len;		/* set the new key */
      salt = len;		/* set the new salt */
      return;
    }
  while (len--)
    {				/* for every character in the buffer */

      cc = *bptr;		/* get a character out of the buffer */

      /* only encipher printable characters */
      /* was: if ((cc >= ' ') && (cc <= '~')) */
      if (isprint (cc))
	{

/**  If the upper bit (bit 29) is set, feed it back into the key.  This
    assures us that the starting key affects the entire message.  **/

	  key &= 0x1FFFFFFFL;	/* strip off overflow */
	  if (key & 0x10000000L)
	    {
	      key ^= 0x0040A001L;	/* feedback */
	    }

/**  Down-bias the character, perform a Beaufort encryption, and
    up-bias the character again.  We want key to be positive
    so that the left shift here will be more portable and the
    mod95() faster   **/

	  cc = mod95 ((int) (key % 95) - (cc - ' ')) + ' ';

/**  the salt will spice up the key a little bit, helping to obscure
    any patterns in the clear text, particularly when all the
    characters (or long sequences of them) are the same.  We do
    not want the salt to go negative, or it will affect the key
    too radically.  It is always a good idea to chop off cyclics
    to prime values.  **/

	  if (++salt >= 20857)
	    {			/* prime modulus */
	      salt = 0;
	    }

/**  our autokey (a special case of the running key) is being
    generated by a weighted checksum of clear text, cipher
    text, and salt.   **/

	  key = key + key + cc + *bptr + salt;
	}
      *bptr++ = cc;		/* put character back into buffer */
    }
  return;
}


char *
xx_encrypt (char *keystr, char *str)
{
  assert (NULL != keystr);
  ue_crypt (NULL, 0);
  ue_crypt (keystr, (int) strlen (keystr));
  assert (NULL != keystr);
  ue_crypt (str, (int) strlen (str));
  return str;
}


#ifdef TEST_CRYPT
int
main (int argc, char *argv[])
{
  char str[1024];
  char keystr[1024];

  if (argc == 3)
    {
      strcpy_ck (keystr, argv[1]);
      strcpy_ck (str, argv[2]);
    }
  else
    {
      printf ("Usage: ec2crypt <key> <string>\n");
      exit (0);
    }

  printf ("key: %s\n", keystr);
  printf ("string: %s\n", str);
  printf ("keylen: %d\n", strlen (keystr));
  printf ("stringlen: %d\n", strlen (str));
  printf ("encrypted: %s\n", xx_encrypt (keystr, str));

  return (0);
}
#endif